Analytical Report

NETW360, Professor Abraham Kizner

05/16/2012

Lab #3, Hidden Node

Lab Report

1. In your opinion, what is the purpose of our dropping the Transmit Power to such a low level?

In the United States:

When using omni-directional antennas having less than 6 dB gain in mobile WLAN scenarios, the FCC rules require EIRP to be 1 watt (1,000 milliwatts) or less. The EIRP limitations for fixed, point-to-point systems that use directive antennas with at least 6 dBi gain is 4 watts.

2. What does Access Point Connectivity statistic connected for the roaming station show?

The Access Point Connectivity statistics collected show that the data remains the same. AP Connectivity remained constant throughout the 30 seconds of the simulation.

3. What do you think the Wireless LAN control traffic received by the roaming 11b node when it is in the Engineering building, is composed of?

It contains random outcomes for the size of generated packets (specified in bytes).

4. How much did our roaming node reduce the total throughput in our heavily loaded wlan?

When the simulation started, throughput was at 25,500,000 bits/sec. At 14 seconds which is when the roaming node entered the engineering building, throughput dropped to about 21,600,000 bits/sec at a loss of 3,900,000 bits/sec. At it left (at around 18 seconds), throughput went up to 25,500,000 bits/sec.

5. What caused this reduction in “goodput” on the 11g WLAN?

Interference of the roaming node most likely caused it as we see the throughput drop when it enters the range of the 11g WLAN

6. Supposedly, 802.11b is “backwards compatible” with 802.11g yet this lab demonstrates there are significant problems with allowing the two to coexist. What is the primary “incompatibility” between b and g?

Appliances may interfere on the unregulated signal frequency

7. There is another mechanism besides RTS/CTS that helps the incompatibility....